Although tremendous developments have taken place in recent years in the sophistication and computing power of hand-held calculators, the very diminutive size and low power requirements of these devices have perpetuated their major drawback. That is, a printout device having low current requirements has not been made commercially feasible.
It has been shown that most of the errors introduced into computations made with hand-held calculators are due to input errors or to mistakes in transferring the answer from the readout to paper. Due to the low current availability of these small, portable devices having small batteries, the readout portion of these machines has generally been limited to visual displays such as LED segment displays, liquid crystal light reflecting displays, or the like. The power requirements and size of prior art printout devices have made them incompatible with hand-held calculators. The lack of hard copy printout from these machines has been their major drawback.